SEATTLE (AP) — Washington Gov. Jay Inslee and Secretary of State Kim Wyman said Tuesday that Washington state will pay for prepaid postage on mail-in ballots in this year's primary and general elections in an attempt to boost turnout — but not for voters in King County, where local officials approved their own measure last week.

The decision Tuesday came at Wyman's request and was prompted by King County's plans. Wyman said it would be unfair if voters in the most populous county could mail their ballots for free while those elsewhere had to pay for stamps, and she asked Inslee to let her spend nearly $2 million to reimburse all 39 counties on prepaid postage this year.

Instead, she and the governor issued a statement saying their offices could each come up with $600,000 — enough to reimburse all counties except King, where roughly one-third of Washington's registered voters live, and where the County Council voted last week to spend $381,000 for the prepaid postage.

They said they'll ask the Legislature next year to reimburse King County — and to make Washington the first state with a permanent prepaid ballot program.

"More voter participation makes for a stronger democracy," Inslee said. "Because Washington is a vote-by-mail state, pre-paid postage is one important way we can reduce barriers to casting ballots."

The decision to exclude King County from immediate reimbursement infuriated its officials. In a joint statement, county Executive Dow Constantine, Council Chair Joe McDermott and Elections Director Julie Wise said: "We are proud that our leadership spurred statewide action to increase voting access across Washington. However, the decision to exclude King County — and only King County — from the state reimbursement plan for prepaid ballot postage is grossly unfair."

They said the county's residents contribute a disproportionate share of the state's budget, and that if the state cannot afford to reimburse all counties for ballot postage, it should provide a per-voter subsidy statewide.

McDermott said he had little faith the Legislature would pony up money for the county's costs next year.

"It's a game of roulette to go to the Legislature and ask for reimbursement after the fact," he said.

He also noted that the decision would affect cities and school districts within King County, because smaller jurisdictions with local elections — for school board or city council, for example — share ballot costs with the county.

Washington has taken several steps recently to improve voter turnout. Earlier this year, the Legislature approved automatic voter registration, in-person registration on election days, and a program to pre-register 16- and 17-year-olds to vote.

While voter participation in the state approached 79 percent during the presidential election year in 2016, last year's turnout statewide was 37 percent.

Nearly 600 offices are in play in Washington this year, including that of Democratic U.S. Sen. Maria Cantwell, all 10 U.S. representatives, more than 120 seats in the Legislature and three state Supreme Court seats.

Greg Kimsey, the elected auditor in Southwest Washington's Clark County, said he wasn't convinced that prepaid ballot postage would boost turnout, but he said he supports the plan nevertheless.

"Increasingly, people are just not accustomed to using the post office," he said. "My children, who are in their 20s — I think it's been a long time since they've put a stamp on an envelope and put it in the mailbox."